A compression refrigeration ice maker has evaporator coils in close thermal contact with the ice-forming mold. Such ice making machines typically employ a small water circulating pump to circulate water over the mold to build up the desired ice forms. Pumps that are used for this purpose are commonly combined with, and driven by, an electric motor which is vented to prevent the motor from overheating.
In the operation of commercial ice making machines, such as in motels, restaurants and the like, one of the most frequently occurring problems is failure of the electric motor. Conventional motors for ice making machines are particularly susceptible to bearing failure. Such motors are typically selected without regard to the pumping loads, and consequently tend to run hot. This greatly contributes to bearing failure. Venting the motor also contributes to bearing failure, since the circulating water can reach the bearings of the motor through the vents and wash out the lubricant.
The design of the pump itself can also contribute to bearing failure. The housings of currently available pumps often present substantial flow restrictions. Such restrictions compel manufacturers to specify larger motors, which in turn develop more heat. This heat not only diminishes the useful life of the electric motor, but also detracts from the overall efficiency of the ice making machine.
A further deficiency in the design of the standard pump assembly resides in the presence of recesses in areas where water may be splashed or circulated. Such recesses can result in undesirable flow characteristics, and can trap bacteria and fungus, and other harmful organisms.